1. Field of the Invention
The present invention relates to digital image processing, and more particularly relates to an edge-oriented interpolation method and system for a digital image, which is especially useful to enhance image interpolation at edge portions of the digital image.
2. Description of the Related Art
Linear interpolation such as bilinear and bi-cubic interpolation is very fundamental to many digital image processing operations such as scaling, rotation, translation and geometric correction. Yet such interpolation fails to settle the blurring or the jagging of edges as a basic problem in image interpolation so far.
Bilinear interpolation has less computation and a low cost, but results in images with unpleasant blurring artifacts, especially when displayed on a large-scale display such as a 42 inch LCD panel or a 42 inch plasma panel. This is mostly due to the color averaging in bilinear interpolation.
In contrast, bi-cubic interpolation is much more complicated and costly. Although bi-cubic interpolation may result in images of a better appearance than bilinear interpolation, bi-cubic interpolation may also introduce jagging edges in the enlarged images, especially near sharp edges such as boundaries of dark colored texts against a light colored background.
Therefore, there is a need for an edge-oriented interpolation method and system for a digital image, which is especially useful to enhance image interpolation at edge portions of the digital image.